Steadier for elongated workpieces and mandrel bars



H. C. INSLEE May 1, 1945.

STEADIERS FOR ELONGATED WORKPIECES AND MANDREL BARS Filed sew. s, 1945 s Sheets-Sheet 1 ATTORNEY I May 1,: 1945. H. c. INSL EE- 2,374,939

STEAD IERS FOR ELONGATED WORKPIECES AND MANDREL BARS I Filed Sept. :5, 1943 s Sheets-Sheet 2 ill MATT'ORNEY- y 1, 1945- H. c. INSLEE 2,374,939

7 STEADIERS FOR ELONGATED WORKPIECES AND MANDREL BARS Filed Sept. 5, 1943 3 Sheets-Sheet 3 izvvswroa. $12 I I a HTTOIPNE) Patented May 1, 1945 UNITED STATES PATENT FFICE STEADIER FOR ELONGATED WORKPIECES 3 i AND MANDREL BARS i ,Heber C. Inslee, East Orange, N. J., assignor, by

mesne assignments, to Rockrite Processes, Inc., Stamford, Conn., a corporation of Delaware Application September 3, 1943, Serial No. 501,104

(Cl. s0 14) 15 Claims.

to the invention are adapted for and may be used in other tube reducing mills and. inmills for reducing solid bars or rods. I

In the duplex tube reducing mill shown in said application, the tubes are reciprocated by reciprocating members which grip the rear ends of the tubes and which are mounted in a longitudinally movable tube unit housing which is given a slow forward movement to feed the tubes to the dies and is returned to starting position with a quick backward movement for the positioning of new tubes; and the mandrels are carried by long mandrel bars which are reciprocated but are not fed forward. When said housing is in its starting position and until ithas rnade a considerable part of its forward movement for feeding the tubes between'the dies,

the long length of the tubes between the tube reciprocating members and 'the dies needs"to be supported and steadied, but thesteadying and supporting device must be withdrawn from the path of the advancing housing; and after the housing has been made a considerable part of its forward movement, the long length of tion and operated to close about the tube, or about themandrel rod, asit may be, after being moved into operative position and to open before being withdrawn from operative position, and means whereby as'the tube unit housing is fed forward the tube steadiers, in Order .to avoid interference with the forwardly moving housing, Will be withdrawn after being first opened, and whereby the mandrel bar steadiers'will be moved into operative position and then closed about the mandrel bars during the forward movement of the tube runit housing, and will be opened and withdrawn during th quick return movement of the housing in time to avoid interference with the housing, and means for positioning and closing the tube steadier after A full understanding of the invention can best be given by a detailed description of an embodiment of the various features of .the invention as applied to a duplex pilger-type tubereducing mill of the kind referred to, and such a description will now be given in connection with the accompanying drawings, in which:v

Fig. 1 is a plan view of the duplex tube reducing mill shown in my said application Serial No. 442,769;

Fig. 2 is a side elevation of the mill;

Fig. 3 is a view showing, partly in section and partly in elevation, the mandrel bar steadier unit looking toward the left in Figs. land 2, the main framing and certain other parts of the mill being indicated in dotted lines;

the mandrel bars between the rear ends of the withdrawn from the path of the housing as it makes its return movement. An object of the invention is to provide steadier mechanism for such duplex tube reducing mills and for single tube reducing mills where a similar cycleof movements of steadiers is required withrelation to the movements of a tube feeding member, features of the invention being, as stated, adaptable for use in other types of tube reducing mills, and in pilger mills or other mills for reducing solid bars and rods. I

Steadier mechanism according to the'invention for such a duplex mill comprises one 01' more steadiers for each tube and one or more steadiers for each mandrel bar, each steadier being movable intoand out of operative posi- Fig. 4 is a side view of the mandrel bar steadierunit; and .Fig. 5 is a wiring diagram showing a circuit arrangement and reversing switches for the motors by which the steadiers are moved into and out of operative position, and the switch operating levers which are operated by tappets on the longitudinally movable housing in which the tube reciprocating members are mounted.

The tube reducing mill illustrated is a duplex mill having two axially spaced pairs of continuously driven gapped working rolls andmeans for reciprocating a mandrel and tube between the rolls of each pair, and means whereby the tubes and mandrels are given a partial turn and the tubes are given an increment of feed between successive working strokes, the working rolls having, in the usual manner, tapered die grooves which act on the tubes during the work ing stroke of the tubes and mandrels, the rolls rotating without contact with the tubes during the non-working return stroke'of the tubes and mandrels. The reducing action takes place during the backward stroke of the tubes and mandrels.

Referring to the drawings, and first to Figs. 1 and 2, the mill shown comprises a roll stand ID, a mandrel reciprocating and turning unit II, a tube reciprocating, turning and feeding unit [2, tube feeding mechanism l3, reciprocating mechanism l4, and an exit tube reciprocating and turning unit l5.

The roll stand comprises a massive frame or housing 20 in which are mounted two pairs of overhung die rolls 2| and 22 fast on opposite ends of two shafts journaled within the housing, and two pairs of backing rolls 23 and 24. At the entrance side of the housing 20, there are two tube clamping devices 25 of which one is shown in Fig. 2. These clamping devices are open during the operation of the mill and are closed to clamp the rear ends of the partially reduced tubes when the mill isstopped.

The operating parts of the mandrel reciprocating and turning unit are mounted in a stationary housing 30 seated on the rear end of a longitudinally extending base 3|. These operative parts are driven by a transverse driving shaft 32'which is oscillated by the reciprocating mechanism I4. Mounted fast on shaft 32 are two lever arms 33, one on each side of the housing, one of which is shown in Fig. 2. Each of these arms reciprocates one of the two mandrel bars 40 each of which has at its forward end a tapered mandrel. Each of the mandrel bars extends through and is detachably secured by means of a clamp 4| to a longitudinally reciprocable and axially rotatable sleeve 42. The forward end of each sleeve 42 is rotatably connected to a sliding member 43 which is reciprocated by one of the arms 33 through a link 44.

Two longitudinal rock shafts 50 extend forward one from each side of the mandrel unit housing 30. Each of these rockshaft 50 is oscillated by the drive shaft 32 through a segment gear 52 on the drive shaft meshing with a beveled pinion 53 on the shaft 50.

The tube-reciprocating, turning and, feeding unit l2 comprises a housing 60 mounted to slide on the base 3| between the position shown by full lines in Figs. 1 and 2 and that indicated by dotted lines in Fig. 2. As in the case Of the mandrel unit, this tube unit is a duplex unit having duplicate operating parts arranged symmetrically with respect to a vertical longitudinal plane for reciprocating and turning two tubes on the two mandrels and mandrel bars. For each tube T there is a longitudinally reciprocable and axially rotatable sleeve 6| through which one of the mandrel bars extends and to the forward end of which the tube is detachably secured by a clamp 62. The rearward end of each of the sleeves 6| is connected to a sliding member 63 which is connected by a link 64 to a lever arm 65 extending from a hub rotatably mounted on the end of a cross shaft 66. Each of these hubs carries also a bevel gear segment 61 which meshes with a bevel pinion 68 carried by a sleeve which is' slidable on one of the shafts 50 and splined thereto so as to be turned thereby, and which is also mounted in a bearing 69 on the housing 60 by which it is held against movement longitudinally with respect to thehousing. By oscillation of the shafts 50, therefore, the arms 65 are oscillated and the sleeves BI and the tubes secured thereto are reciprocated. The arms 65 of the tube unit and the arms 33 of themandrelunit have the to give an increment/of feed to the tubes.

same angular motion and are of the same effective radial length and are driven in unison, so that the tubes and mandrels are given equal and synchronous reciprocations.

During each non-working forward stroke of the tubes and mandrels, the tube unit housing 60 is given a short forward feeding movement by which the tubes are given an increment of feed with relation to the mandrels. This stepby-step forward feeding of the tube unit is effected by a pinion I0 driven, through a one-way clutch of the tube feeding mechanism I3, from one of the shafts 50, the pinion meshing with a rack 1| extending backward from the tube unit housing through aguide opening in the stationary housing 30 of the mandrel unit. This pinion and rack serve also for giving a quick return movement to the tube unit when, after being disconnected from the nearly completed tubes, it

is to be moved back for the positioning of new tubes, the pinion being then disconnected from the one-Way feeding clutch and being driven by a motor 12 which is under push-button control.

As the reduced portions of the tubes advance beyond the die rolls "they are engaged by reciprocating friction clamps of the exit tube reciprocating and turning unit l5. These friction clamps 85 of the exit unit permit slippage under the increment of feed of the new tubes during each non-working stroke and slippage during the working stroke due to the elongation of the tubes.

In the operation of the mill, after each working stroke of the tubes and mandrels, during which a length of the tubes is pressed between working portions of the grooves of the die rolls, the tubes are released by the die rolls, and the tubes and mandrels then make a forward return stroke during which they are given a partial turn and the tube unit housing 60 is moved forward When the housing 30 has been advanced to its extreme forward position, as shown by full lines in Figs. 1 and 2, the mill is stopped and the unreduced rear ends of the tubes are clamped by the clamps 25. The sleeves 6| of the tube unit are then disconnected from the tubes and the mandrel bars are disconnected from the mandrel unit, and the housing 60 is moved backward to its extreme retracted position indicated by dotted lines in Fig. 2, and the mandrel bars are drawn back, by suitable means not shown, until the forward ends of the mandrels are back-of the tube clamps of the retracted'tube unit. New tubes are then brought into position in the mill and their rear ends are secured by the clamps 62. The mill may then be again started in operation.

The mill as so far described is more fully shown and described in my said application S. No. 442,769. In said application, the tube and man- 'drel bar steadier units of the invention of the present application are shown as they are shown in Figs. 1 and 2 of the present application. As shown herein and in said application, one tube steadier unit is provided having two steadiers. that is, one for each tube, and one mandrel bar steadier unit is provided having two steadiers, one for each mandrel bar. This has so far been found sufficient, but the invention is not to be limited to the provision of only one steadier for 'each tube or for each mandrel bar.

As shown in Figs. 1 and '2, the two steadier units H0 are mounted on a longitudinally extending beam Ill supported at one end by the roll stand housing 20 and at the other end by the mandrel uni-t housing 30, the steadier units being positioned-lengthwise of the beam II I, most desirably so that the tubes may be steadied and supported at a point about midway between the roll stand and the forward-end of the tube unit housing when it is in its rearmost position,'but preferably somewhat nearer to the roll stand, and that the mandrel bars may be steadied and supported at a point about midway between the forward end of the mandrel unit housing and the rear end of the tube unit housing when the latter is in its forwardmost position.

The tube steadier unit and the. mandrel bar steadier unit may be, and mostv desirably are, of the same construction except that the tube and mandrel bar engaging members, or steadiers proper, II2, are. of difierent size to suit the size of the tube and mandrel bar respectively. Figs. 3

the two jaws ofeach steadier have been turned on. their pivots toward each other by the links I25 to close the steadiers about the mandrel bars, or tubes, the motor circuit then being opened by a suitably placedlimit switch or otherwise. When the operating members are moved upward,the steadiers are first opened by relative movement between the operating members and the carriers,

' and then, after the steadiers have been opened and 4 illustrate a steadier unit of preferred con-v I struction for a duplex mill such as shown in Figs. 1 and 2. This steadier unit comprises a cast metal or other frame having two vertical-slideway housings I I5 'connecte'd by. a middle cross plate I I6 and a top cross plate I I7. Thecross plate I I 6 seats on the top of the beam I I I with the lower portions of the guideway housings straddling the beam. Fitted within each of'the slideway housings I I5 to move vertically therein is a carrier I from the bottom of which extend two spaced bracket plates I2I. Each steadier H2 is formed by two pivoted jaws having convexly curved engaging faces, most desirably semi-cylindrical, 'to fit about the m'andrel bar, or, as the case may be, the tube, andthe two jaws of each steadier are independently pivoted on a pivot pin extending between the two plates I2I of the carrier I 20 and each has a short v arm I24 which is connected by an adjustable link I25 to an operating member I26 sleeved carrier. V 1

The operating members I26 are. drawn upward to raise the carriers I20 for withdrawing the steadiers and are moved downward to permit the carrier to move downward for moving the steadiers into operative position by means of two screws I30 rotatably held in bearings in the top plate I I1, each screw extending through a nut I3I in the upper end of one of the operating members I26, which are hollow and of a length to receive the screws when the operating members and carriers are in upper position. Thetwo screws are turned by means of a reversible electric motor I mounted on the beam I I I and, most desirably and within the as shown, on a plate I36 extending from between V the beam and the cross plate II6'. The'motor drives a shaft I31 at reducedspeed through a worm gear unit I38 and a slip coupling I39, and the shaft I31, extending through a bearing in the top plate I I1, has fast on its upper end a driving pinion I40 by which pinions I 4| fast on the upper end of the screws I30 are driven through intermediate gears I42.

Each of the carriers I20 has an inwardly projecting shoulder I to rest ona shoulder I46 on its operating member I26, so that, when these shoulders are in engagement, if the operating members are moved upward the carrier are moved upward withthem, and if the operating members are moved downward the carriers drop with them. Adjustable stops on the carriers, formed by screws I41, limit the downward movement of the carriers by engagement with lugs on the housings II 5 when the carriers have lowered their steadiers to operative position above the mandrel bars, or tubes; The downward movement of the operating members then continues until by other manual control.

and the shoulder I46 of the operating members have come into engagement with the shoulders I45 of the carriers, the steadiers are withdrawn as the carriers are, by continued upward movement'of the operating members, raised to withdraw the steadiers until the steadiers have been raised above the path of the tube unit housing, whereupon the motor circuit i opened by a limit switch or otherwise. i e

The tube steadiers motor is caused to operate to move the tube steadiers down into operative position when new tubes have been positioned in the mill and to close them about the tubes, and to open and withdraw them during the for-- ward movement of the tube unit housing in time toavoid their being struck by the housing; and

the mandrel bar steadiers motor is caused to operate to move the mandrel bar steadiers down to operative position and close them about the mandrel bars during the forward movement of the tube unit housing when the housing has mo ved beyond them and to open and withdraw them out of the path of the housing during its return movement in time to avoid theirbeing struck. Most desirably, the motor circuits are controlled by movement of the tube unit housing for opening and withdrawing the tube steadiers, and for positioning and .closing and for opening and withdrawing the mandred bar steadiers. For causing the tube steadiers motor to operate to position. and close thetube steadiers, the motor circuit is most. desirably under push-button or A suitable arrangement of circuits and reversing switches and operating levers operated by tappets on the tube'unit hous ing is shown diagrammatically in Fig. 5.

In the wiring diagram, Fig. 5, the two motors I35a and I35b, are indicated as shunt wound reversing motors, the current to the field winding of the tube steadiers motor I35a being controlled by a pole-changing reversing switch I50, and the current to the field winding of the mandrel bar steadiers motor I35b being controlled by a polechanging reversing switch I5I. The motors are supplied with current from feed lines A and B. The switches I50 and I5I are shown in Fig. 5 in position for causing the motor I35a to operate to lower and close the tube steadiers and for causing motor I351) to operate to open and raise the mandrel bar steadiers. When by operation of either motor its steadiers have been raised to their upper withdrawn position, operation of the motor is stopped by a limit switch, indicated at Lu in Fig. 5, and when by operation of either motor its steadiers have beenlowered to operative position and closed, operation ofthe motor is stopped by a limit switch indicated at Ld in Fig. 5.

Switch I5I is shifted in both directions by a lever I54 which in its normal position extends into the path of a trip-cam I55 on the tube unit housing to be operated by thecam during movement of the housing in either direction, and switch I50 is shifted by a lever I52 which in its normal position extends into th path of a one-way tripper I53 on the housing 60 to be I56 under push-button control or other suitable manual control. The levers I52 and I54 have slot and pin connections with the operating rods I58 and I59 of the switches, and after being rocked in either direction to shift the switches the levers are return by springs I60 and IBI 'to their normal positions in which they project into the path of the tappets.

What is claimed is:

1.'In a tube reducing mill having a pair of gapped die rolls mounted to rotate about fixed axes, a mandrel carried by a mandrel bar, a mandrelreciprocating member for gripping the rear end of the mandrel bar, a tube-reciprocating member for gripping the rear end of the tube, means for reciprocating the mandrel-reciprocating member and the tube-reciprocating member, means for giving an increment of forward feed to the tube-reciprocating member for each complete reciprocation of said members, and means for withdrawing the tube-reciprocating member for the placing of a new tube: a mandrel bar steadier and a tube steadier each movable into and out of operative position, means for moving the tube steadier into operative position to steady a new tube, automatically acting means for withdrawing the tube steadier during the forward feeding movement of the tube-reciprocating member, and automatically acting means for moving the mandrel bar steadier into operative position during the forward feeding movement of the tube reciprocating member and for withdrawing the mandrel bar steadier during the backward movement of the tube-reciprocating member.

2. In a tube reducing mill having a pair of gapped die rolls mounted to rotate about fixed axes, a mandrel carried by a mandrel bar, a mandrel-reciprocating member for gripping the rear end of the mandrel bar, a tube-reciprocating member for gripping the rear end of the tube, a longitudinally moveable housing in which said tube-reciprocating member is mounted, means for reciprocating the mandrel-reciproca ing member and the tube-reciprocating member, means for giving an. increment of forward feed to said housing for each complete reciprocation of said members,-and means for withdrawing said housing for the placing of a new tube: a mandrel bar steadier and a tube steadier each movable into and out of operative position, means for moving the tube steadier into operative position to steady a new tube, and means controlled by movement of said housing for withdrawing the tube steadier during the forward movement of said housing, and means controlled by movement of said housing for moving the mandrel bar steadier into operative position during the forward movement of said housing and for withdrawing it during the backward movement of said housing.

3. 'In a tube reducing mill having a pair of reducing dies, and a mandrel'carried by a mandrel bar,-and"a tube feeding member for engaging'the rear end of the tube, and means for'moving said "member forward step-by-step and'for withdrawing said'member for the placing of a new tube: a mandrel bar steadier and a tube steadier each movable into and out of operative position, means for moving the tube steadier into operative position to steady a new tube, automatically acting means for withdrawing the tube steadier during the forward movement of the tube-feeding member, and automatically acting means for moving the mandrel bar steadier into operative position during the forward movement of the tube-feeding member and for withdrawing it during the backward movement of the tube-feeding member.

4. In a tube reducing mill having a pair'of reducing dies, and a mandrel carried by a mandrel bar,'and a tube feeding member for engaging the rear end of the tube, and means for moving said member forward step-by-step and for withdrawing said member for the placing of a new tube: a mandrel bar steadier movable .into and out of operative position, and automatically acting mean for moving the mandrel bar steadier into operative position during the forward movement of the tube-feeding member and for withdrawing it during the backward return movement of the tube-feeding member.

5. In a tube reducing mill having a pair of reducing dies, and a mandrel carried by a mandrel bar, and a .tube feeding member for engaging the rear end of the tube, and means for moving the tube feeding member forward step-by-step and for withdrawing said member for theplacing of a new tube: a tube steadier movable into and out of operative position, means for moving the tube steadier into operative position to steady a new tube, and automatically acting means for withdrawing the tube steadier during the forward movement of the tube feeding member.

6. In a reducing mill having a pair of reducing members, and a feeding member for engaging the rear end of an elongated workpiece, and means for moving said feeding member forward to feed the workpiece to the reducing members and for withdrawing said feeding member for the placing of a new workpiece: a workpiece steadier movable into and out of operative position, and automatically acting meansjor withdrawing said steadier during the forward movement-of the feeding member.

7.. In a tube reducing mill having a pair of gapped die rolls mounted to rotate about fixed axes, a mandrelcarried by a mandrel bar, a mandrel-reciprocating member for gripping the rear end of the mandrel bar, a tube-reciprocating member for gripping the rear end of the tube, means for reciprocating the mandrel-reciprocating member and the tube-reciprocating member, means for giving an increment of forward feed to the tube-reciprocating member for each com-v plete reciprocation of said members, and means for withdrawing the tube-reciprocating member for the placing of a new tube: a mandrel bar steadier and a tube steadier each movable into and out of operative position and each adapted to beopened and closed when in operative position, means for moving the tube steadier into operative position and closing it to steady a new tube, automatically-acting means for opening and then withdrawing the tube steadier during the forward movement of the tube reciprocating member, and automatically acting means for moving th :mandrel 'bar steadier into operative position and then closing'it during the forward a new tube: a mandrel bar steadier and a tube V steadier each movable into and out of operative position and each adapted to be opened and closed when in operative position, means for mov-- ing the tube steadier into operative position and closing it to steady a new tube, automatically acting mean for opening and then withdrawing the tube steadier during the forward movement of the tube-feeding member, and automatically acting means for moving the mandrel bar steadier into operative position and then closing it during the forward movement of the tube-feeding member and for opening and then withdrawing the mandrel bar steadier during the backward return movement of the tube-feeding member.

9. In a tube reducing mill having a pair of reducing dies, and a mandrel carried by a mandrel bar, and a tube-feeding member for engaging the rear end of the tube, and means for moving the tube feeding member forward step-by-step and for withdrawing said member for the placing of a new tube: a tube steadier movable into and out of operative position and adapted to be opened and closed when in operative position, means for moving the tube steadier into operative position and closing it to steady a new tube, and automatically acting means .for opening and then withdrawing the tube steadier during the forward feeding movement of the tube feeding member.

members, and a feeding member for engaging the rear end of an elongated workpiece, and means for moving said feeding member forward to feed the workpiece to the reducing members and for withdrawing said feeding member for the placing of a new workpiece: a workpiece steadier movable into and out of operative position and adapted to be opened and closed when in operative position, and automatically acting mean for opening and then withdrawing said steadier during the forward movement of the feeding member.

11. In a duplex tube reducing mill having two axiallyspaced pairs of gapped die rolls mounted to rotate about a fixed axis, a mandrel carried by a mandrel bar for coacting with each pair of die rolls, two horizontally spaced mandrelreciprocating members each adapted to grip the rear end of one of the mandrel bars, two horizontally spaced tube-reciprocating members each adapted to grip the rear end of a tube, a longitudinally movable housing in which said tube-reciprocating members are mounted, means for reciprocating the mandrel-reciprocating members and the tubereciprocating members, means for giving an in crement of forward feed to said housing for each complete reciprocation of said members, and means for withdrawing said housing for the plac ing of new tubes: a beam extending longitudinally above the path of movement of said housing, a tube steadier unit mounted on said beam comprising two tube steadiers and operative means 10. In a reducing mill having a pair of reducing for moving said steadiers vertically intoand out of operative position and for closing and opening them when in operative position, and a mandrel barsteadier unit mounted on said beam comprising two mandrel bar steadiers and operating means for moving said steadiers vertically into and out of operative position and for closing and opening them when in operative position.

12. In a duplex tube reducing mill having two axially spaced pairs of gapped die rolls mounted to rotate about a fixed axis, a mandrel carried by a mandrel bar for coacting with each pair of die rolls, two horizontally spaced mandrel-reciprocating members each adapted to grip the rear end of one of the mandrel bars, two horizontally spaced tube-reciprocating members each adapted to grip the rear end of a tube, a longitudinally movable housing in which said tube-reciprocating members are mounted, means for reciprocating the mandrel-reciprocatingmembers and the tube-reciprocating members, means for giving an increment of forward feed to said housing for each complete reciprocation of said members, and means for withdrawing said housing for the placing of new tubes: a beam extending longitudinally above the path of movement of said housing, a tube steadier unit mounted on said beam comprising two tube steadiers and operative means for moving said steadiers vertically into and out of operative position and for closing and opening them when in operative position, a mandrel bar steadier unit mounted on said beam comprising two mandrel bar steadiers and operating means for moving said steadiers vertically into and out of operative position and for closing and opening them when in operative position, manually operable means for causing the operating means of the tube steadier unit to move the tube steadiers into operative position and then close them, means controlled by movement of said housing for causing the operating means of the tube steadier unit to open and withdraw the tube steadiers during the forward feeding movement of said housing, and means controlled by the movement of said housing for causing .the operating means of the mandrel bar steadier unit to move the mandrel bar steadiers into operative position and close them during the forward movement of said housing and to open and then withdraw the mandrel bar steadiers during the backward movement of said housing.

13. In a duplex reducing mill having two laterally spaced pairs of reducing members, and two laterally spaced feeding members for engaging the rear end of elongated workpieces, and means for moving said feeding members forward to feed the workpieces to the reducing members and for withdrawing said members for the placing of new workpieces: a workpiece steadier unit mounted above the path of movement of said feeding members comprising two workpiece steadiers and operating means for moving the steadiers vertically into and out of operative position and for closing and opening them when in operative position, means for causing the operating means of the steadier unit to move the steadiers into operative position and then close them about newly positioned workpieces, and means controlled according to the movement of said feeding members for causing said operating means to open and withdraw the steadiers during the forward movement of the feeding members.

14. A steadier unit, comprising a vertically movable carrier, a steadier carried by said carrier at its lower and adapted to be opened and-closed,

a vertically movable operating member adapted to make lifting engagement with the carrier whereby when the operating member moves upward the carrier is raised and when the operating member moves downward the carrier is permitted to move downward, a stop for limiting downward movement of the carrier, means connecting the steadier to said operating member whereby on continued downward movement of the operating member after downward movement of the carrier has been stopped the steadier is closed and on upward movement of the operating member rela tively to the carrier before the carrier is lifted the steadier is opened, and means for moving the operating member downward to lower and then close the steadier and for moving the operating member upward to open and then raise the steadier.

15. A steadier unit, comprising a carrier, a steadier carried by said carrier formed of two jaw members pivoted; to swing toward and from each other, an operating member sleeved within the carrier and adapted to cause inward movement of the carrier for positioning the steadierand outward movement of the carrier for Withdrawing the steadier, a stop for limiting inward movement of the carrier, links connecting the jaw members of the steadier to the operating member whereby on continued inward movement of the operating member after inward movement of the carrier has been stopped the steadier is closed and on outward movement of the operating member relatively to the carrier before the carrier is moved outward the steadier is opened, and mean for moving the operating member inward to position and then close the steadier and for moving the operating member outward to open and then Withdraw the steadier.

HEBER C. INSLEE. 

